View clinical trials related to Magnetic Resonance Imaging.
Filter by:The purpose of this study is to investigate the organization of memory and develop future methods for early detection of AD. Using functional magnetic resonance imaging (fMRI), we examine the responsiveness of the brain to memory tasks, specifically focusing on regions of the brain (the mesial temporal lobe and posterior cingulate) that are known to be involved in early stages of Alzheimer's disease (AD). Of interest are differences in brain activation between people with and without a family history of AD and other risk factors.
The purpose of this study is to use fMRI techniques to explore a certain part of the brain associated with Alzheimer's disease known as the posterior cingulate. Determining the functionality of this brain region may help us diagnose AD more accurately, thus allowing earlier treatment.
In this clinical study a contrast agent for magnetic resonance imaging (MRI), which has already been approved for application in adults, will be investigated in children and adolescents. MRI is a modern and safe examination method without delivering radiation burden using magnetic fields to produce cross-sectional images of the human body. A special computer program then puts these images together and creates a two or three-dimensional image of the inner organs thus facilitating the detection and evaluation of pathological changes. In contrast-enhanced MRI a contrast agent is injected into a peripheral vein before the examination which results in a stronger contrast in the examined area. Therefore, pathological changes can be more easily detected and evaluated compared to non-enhanced MRI. The company Bayer HealthCare Pharmaceuticals has developed a contrast agent for MRI called Gadavist 1.0 which was first approved in 1998 in Switzerland for MRI of brain and spine. Since 2003 Gadavist can also be used in magnetic resonance angiography (MRA) in adults, i.e. in the MRI examination of the blood vessels and since 2006 in MRI of liver and kidney disease. Gadavist was examined in more than 2,900 adults within the framework of clinical studies during development and has been used after its marketing authorization in meanwhile more than 600,000 patients. Yet, clinical studies investigating Gadavist have been only conducted with adults so far. Diseases requiring MRI examinations, however, often occur in children, too. Therefore, many contrast agents are already used on a regular basis in MRI examinations of children, some of these contrast agents being authorized already. Within the framework of this study the pharmacokinetic characteristics of Gadavist in children or adolescents will be investigated, i.e. how the contrast agent is distributed and behaves in the body. In addition, safety and tolerability will be evaluated in order to demonstrate that Gadavist 1.0 is a safe and well tolerated contrast agent also for children and adolescents. Furthermore, the study aims to obtain the dosage recommendation of 0.1 ml per kilogram body weight also for this population group.
In elderly patients with atrial fibrillation (AF) the presence of silent brain infarcts and neurocognitive deficit is high despite adequate treatment with oral anticoagulation. Atherosclerosis is considered to be a chronic inflammatory disease and thrombosis and inflammation are strongly correlated. Atrial fibrillation is linked with increased levels of inflammatory markers and intensive cholesterol lowering has proven to reduce inflammation. In a prospective double-blind randomized pilot-study we want to test the hypothesis, that addition of intensive cholesterol lowering treatment besides adequate oral anticoagulation will reduce cerebrovascular lesions and will be beneficial for neurocognitive status in elderly AF patients.
This study will develop new techniques for optimizing resolution in magnetic resonance imaging (MRI) with a high magnetic field of 7 Tesla. MRI is a diagnostic tool that generates high-quality images of the body without the use of x-rays. It can also provide information about brain chemistry and physiology. The test is routinely done at magnetic field strengths of from 1.5 to 4 Tesla. This study will use an investigational device that operates at a high magnetic field of 7 Tesla. Except for the increase in magnetic field, all other aspects of imaging are the same as those at lower magnetic fields. This study will use techniques in conjunction with the higher magnetic field that may improve diagnostic imaging. The MRI will monitor the brain at high resolution to see structural features, to measure brain chemicals, and to determine how much and how fast blood flows into brain regions in response to simple tasks. Healthy normal volunteers 18 years of age and older may participate in this study. Candidates will be screened with a medical history, neurological examination, and questionnaire. Participants will have a standard 1.5 or 3 Tesla MRI before the 7 Tesla scan, adding about 5 minutes to the procedure. The procedure for both scans is the same. The subject lies on a table that is moved into the scanner. Because the machine makes loud sounds during the imaging, earplugs are provided to help reduce the noise. An insulated wire coil may be placed around the subject's head to obtain better images. Scanning time varies from 20 minutes to 3 hours, with most examinations lasting between 45 and 90 minutes. During the scan, the subject may be asked to perform simple tasks, such as listening to tones, tapping fingers, moving a hand, watching a movie on a screen, or smelling pleasant odors. More complex tasks may require thinking about tones or pictures and responding to them by pressing buttons. Following the test, subjects will complete a brief questionnaire about comfort level and any unusual sensations they may have experienced during the test. Participants who undergo repeated MRIs for the evaluation of new techniques will have a standard 1.5 or 3 Tesla MRI brain study once a year while participating in the research protocol. A radiologist at NIH will read the MRIs, and if any abnormalities are discovered, the individual will be referred to his or her private physician or to a consult service at NIH.